UpAndDown.java

package com.rlovep.file;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.tomcat.util.http.fileupload.FileItem;
import org.apache.tomcat.util.http.fileupload.FileItemFactory;
import org.apache.tomcat.util.http.fileupload.FileUploadException;
import org.apache.tomcat.util.http.fileupload.disk.DiskFileItemFactory;
import org.apache.tomcat.util.http.fileupload.servlet.ServletFileUpload;
import org.apache.tomcat.util.http.fileupload.servlet.ServletRequestContext;

/**
 * Servlet implementation class UpAndDown
 */
@WebServlet("/UpAndDown")
public class UpAndDown extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
  
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		String method=request.getParameter("method");
		if("upload".equals(method))
		{
			upload(request, response);
		}else if("downList".equals(method))
		{
			downList(request, response);
		}
		else if("down".equals(method)){
			download(request, response);
		}
	}

	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}
     /**
      * 文件上传
      * @author peace
      */
	private void upload(HttpServletRequest request,HttpServletResponse response){
		//文件上传工厂
				FileItemFactory factory=new DiskFileItemFactory();
				//创建上传核心工具类
				ServletFileUpload upload=new ServletFileUpload(factory);
				//设置单个文件允许的大小：50M
				upload.setFileSizeMax(50*1024*1024);
			    //设置文件上传表单允许的总大小：100M
				upload.setSizeMax(100*1024*1024);
				//设置上传表单文件名的编码：
				upload.setHeaderEncoding("utf-8");
				//文件名前缀
				String prix=null;
				/*
				 * 文件核心处理逻辑
				 */
				//判断当前表单是否为文件上传表单
				if(ServletFileUpload.isMultipartContent(request))
				{
					   
					try {
						 //把请求数据转换为一个个FileItem对象存入List
						List<FileItem> list = upload.parseRequest(new ServletRequestContext(request));
						for(FileItem item :list){
							//判断是否为普通文本数据
							if(item.isFormField())
							{
								// 普通文本数据
								String fieldName = item.getFieldName();	// 表单元素名称
								prix = item.getString();		// 表单元素名称,应的数据
								//item.getString("UTF-8");  指定编码
								System.out.println(fieldName + " " + prix);
							}
							//上传文件
							else{
								// 普通文本数据
								String fieldName = item.getFieldName();	// 表单元素名称
								String name = item.getName();	// 文件名				
								String content = item.getString();		// 文件内容；这个不建议使用；
								//String type = item.getContentType();	// 文件类型
								//InputStream in = item.getInputStream();// 上传文件流
								System.out.println(fieldName+"名字："+name+"content"+content);
								//组装文件名
								name=prix+name;
								//获取存放路径
								String path=getServletContext().getRealPath("/upload");
								System.out.println(path);
								//创建目标文件
								File file=new File(path,name);
								//工具类，文件上传
								item.write(file);
								item.delete();//删除垃圾文件；
							
							}
						}
					} catch (FileUploadException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					} catch (Exception e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
				}
	}
	private void download(HttpServletRequest request,HttpServletResponse response) 
			throws IOException{
		//获取用户下载的文件名称（url地址追加数据，get）
		String fileName=request.getParameter("fileName");
		//对编码转换
		fileName=new String(fileName.getBytes("ISO8859-1"), "utf-8");
		//获取文件下载路径
		String path=getServletContext().getRealPath("/upload");
		//获取一个文件流
		InputStream in=new FileInputStream(new File(path,fileName));
		//文件名是中文，需要进行url编码
		fileName=URLEncoder.encode(fileName, "utf-8");
		//设置下载响应头
		response.setHeader("content-disposition", "attachment;fileName="+fileName);
		//获取response字节流
		OutputStream out = response.getOutputStream();
		byte[] b=new byte[1024];
		int len=-1;
		while((len=in.read(b))!=-1)
		{
			//输出文件流
			out.write(b,0,len);
		}
      out.close();
      in.close();
	}
    private void downList(HttpServletRequest request,HttpServletResponse response) 
    		throws ServletException, IOException{
    	//获取文件名
    	String path=getServletContext().getRealPath("/upload");
    	File file=new File(path);
    	//获取所有文件
    	String[] list = file.list();
    	//将文件名保存到域中
    	request.setAttribute("fileNames", list);
    	//转发
    	request.getRequestDispatcher("/downlist.jsp").forward(request, response);	
    }
}